1. Technical Field
The present disclosure relates to near field communication and related antenna devices.
2. Description of Related Art
Communication systems utilizing Near Field Communication (NFC) techniques may implement data exchange between a reader/writer device and a tag when the reader/writer device and the tag are in close proximity (e.g., less than 10 cm) to each other. The reader/writer device may include a power source and an NFC loop antenna. The tag may include a loop antenna and a memory element. In certain implementations, the tag may be a passive (i.e., unpowered) device. Using the power source and the NFC loop antenna circuitry, the reader/writer device may generate an electromagnetic field that can be used to implement contactless radio communication with the tag. The electromagnetic field generated by the reader/writer device may induce a current flow in the tag, which results in inductive coupling between the reader/writer device and the tag. As a result, data may be exchanged between the reader/writer device and the tag without the need for a physical connection between the two devices. For example, the reader/writer device may transmit an instruction signal to the tag when inductive coupling is established, and the tag may transmit a response signal to the reader/writer device following receipt of the instruction signal.
Communication range for systems implementing NFC techniques is limited and therefore, implementations of such NFC systems may be directed to payment services using a mobile terminal device, where transmissions over a long distance are not necessarily desired. Other implementations of NFC communication systems may be directed to an authentication procedure for various data exchange (e.g., for image and audio data transmission/reception on longer range wireless communication systems).